Rapid Method for Determining Dermal Exposures to Pesticides by Use of Tape Stripping and FTIR Spectroscopy: A Pilot Study

Abstract

Tape stripping is a common method for estimating dermal exposure to pesticides because it is relatively noninvasive and easy to use. A major disadvantage is that samples are usually analyzed with gas chromatography, a time-consuming method in terms of sample preparation. In this study, the authors evaluated the feasibility of using Fourier transform infrared spectroscopy (FTIR) to analyze tape stripped samples to provide near real-time dermal exposure estimates. Various exposure scenarios were evaluated, including a single chemical (i.e., chlorpyrifos, a commonly used pesticide) and a mixture of two chemicals (i.e., chlorpyrifos and captan); these were analyzed with or without the human stratum corneum in the samples. Infrared transparent tape was used for sample collection; samples were analyzed using a FTIR spectrometer in the transmittance mode. The partial least squares algorithm was applied to quantify the spectra and the respective R ² values for calibration, and test samples were larger than 0.99 and 0.90. The percent divergence of this approach was mostly below 10%, except for several low loading samples. The ANOVA test showed that the stratum corneum's influence on the percent divergence was not significant. Although all the samples evaluated in this study were collected from the same human subject, advantages and feasibility of the stripping-FTIR approach were demonstrated.

Keywords:

• dermal exposure
• FTIR
• optical